Fire officials say a central Washington wildfire has burned across more than 20,000 acres of grass and brush, or nearly 32 square miles.

Fire operations spokeswoman Laurie Dowie said Friday night that the Mills Canyon fire was 22 percent contained. More than 760 firefighters were on the lines Friday.

A stretch of U.S. Highway 97A reopened Friday night after a several-hour closure because of firefighting work in the area.

The blaze has threatened more than 200 homes and damaged a few outbuildings in Chelan County near Entiat, roughly midway between Seattle and Spokane.

Residents of several dozen homes have been told to evacuate. No homes have burned.

Spokesman Chuck Turley says a wildfire burning near Spokane was held at less than 2 square miles and is partially contained. That fire is burning near Ford in Stevens County.

Worried that hot, dry conditions would increase fire dangers, state officials have extended an outdoor burn ban to include all 13 million acres of lands that the state protects.